The invention relates to an ice cube apparatus which is designed in particular as a desktop and/or stand-alone unit and is intended in particular for the consumer market.
An ice cube apparatus is known, for example, from U.S. Pat. No. 4,055,053 which, in FIG. 8, shows a housing in which there is a mould chamber. The base of the mould chamber is largely formed by a plurality of mould trays which, on the underside, are connected to thermoelectric elements. The mould chamber is permanently connected to a water system and is kept permanently completely full of water with the aid of a float system. Consequently, the mould trays are always automatically full of water. After the apparatus has been switched to a freezing position, the thermoelectric elements ensure that the water in the mould trays freezes. Then, the power supply to the thermoelectric elements is interrupted, or alternatively these elements are temporarily switched to a heating state, so that heat is supplied to the mould trays for a short time. As a result, the outermost layer of ice melts and the ice cubes are free to float upwards in the mould chamber. The ice cubes can be scooped out of the top side of the mould chamber into an ice bucket with the aid of a chain drive with scoop blades.
A drawback of this known apparatus is that the time which elapses between when the apparatus is switched on and a first series of ice cubes is ready is relatively long. Furthermore, the apparatus comprises a large number of mechanical components, is relatively expensive to produce and is unwieldy. The apparatus can only function with a mould chamber which is completely full, since otherwise the ice cubes which have floated upwards cannot be scooped out of the apparatus. To achieve this, the mould chamber has to be permanently connected to a supply system. The ice cubes which have already been produced remain floating in the water and slowly melt. Furthermore, use of the apparatus is unhygienic, since any contamination remains in the mould chamber and is continuously mixed with fresh water.
Further, FR-A-2,747,769 shows in FIGS. 1 and 2 an apparatus for preparing cold water and ice. Water at ambient temperature can be fed from water bottles which are to be placed on top of the apparatus to a collection bin located inside the apparatus. In a variant, the apparatus may also be connected directly to a water supply system. A controllable valve is provided between the water bottles or the water supply system and the collection tray. From the collection tray, water can be passed via a pump, a system of pipes and a controllable valve to either an external tap or a distribution pipe located inside the apparatus. The distribution pipe is provided with a large number of spray nozzles which are situated just above a cooling body. The cooling body is formed by an inclined, elongate plate with transverse partitions. The spray nozzles atomize water over the cooling body. At one end, the cooling body is connected to a peltier element. In the freezing position of the peltier element, a small amount of the water which reaches the cooling body can freeze on the said body and can grow in layers to a limited extent. The water which does not freeze immediately falls downwards from the cooling body as cooled drops of water and enters the collection bin. At set times, the current direction to the peltier element is reversed, with the result that the bottom layers of ice on the cooling body melt and the discs of ice lying above it slide off the inclined plate and fall onto a collection grate which hangs above the collection tray. On this grate, the discs of ice will begin to melt, the melt water dropping into the collection tray.
It should be noted that this apparatus is intended in particular for the preparation of cold water. The formation of discs of ice is simply a side effect. On the cooling body, it is only possible to freeze ice with a maximum thickness of a few millimeters. The first layers of ice which freeze on the cooling body at the beginning of a freezing cycle provide so much insulation that further progressive growth of ice is impossible. Consequently, only thin discs of ice can be formed. The thin discs of ice will melt away quickly, both on the collection grate and when they are finally used. For this type of combination apparatus, this is more of an advantage than a disadvantage, since the cold melt water contributes to reducing the temperature of the water in the collection bin, which can then be tapped into a glass as cold water via the tap. However, quickly melting discs of ice are very disadvantageous for an ice cube apparatus according to the present invention. This is because in this case cold melt water is an undesirable by-product. The principal product is the production of ice cubes.
Therefore, a drawback of the apparatus described in FR-A2,747,769 is that only a small amount of the water supplied can be effectively converted into ice. Moreover, the ice is of low quality, i.e. it melts very quickly without dissipating much coldness. A further drawback is that the apparatus can only be used in combination with the special bottles which are to be placed on top of the apparatus, or has to be permanently connected to a water supply system. The bottles limit the versatility of the apparatus and, moreover, make it unwieldy and unstable. The water supply system also limits the versatility of the apparatus and, moreover, means that it has to remain in one place. A long time is required to make a first quantity of thin discs of ice. The apparatus has a long start-up time. The water comes out of the bottles at ambient temperature and passes directly into the collection bin, in order then to be cooled slowly by being mixed with water which has been cooled using the cooling body or with melt water. Discs of ice of some thickness can only be made after a sufficiently low temperature of the water in the collection bin has been reached. The mixing is not only slow but also unhygienic, since mixing often takes place with water which has already spent a long time in the apparatus. The thin discs of ice are therefore to a large extent formed from old water.
The object of the present invention is to provide an apparatus with which the only principal product made is ice cubes and in which the above drawbacks are eliminated. In particular, the invention aims to provide an ice cube apparatus which is inexpensive, compact and operates quickly and hygienically and is suitable in particular for the individual consumer who wants to make a small number of ice cubes from fresh water within a short time.
According to the invention, this object is achieved by means of an ice cube apparatus for producing ice cubes, comprising a water reservoir, a housing, a freezing element which is separate from said water reservoir, pump means for supplying water from said water reservoir to said freezing element, at least one thermoelectric element which is connected in a thermally conductive manner to said freezing element, control means with a timer unit for providing current to said thermoelectric element for a defined freezing time, in such a manner that this element extracts heat from said freezing element, removal means for collecting ice which comes from said freezing element, wherein said water reservoir is located entirely inside said housing and comprises a filling opening, via which said water reservoir can be filled with a desired quantity of water, said freezing element being an ice cube tray which comprises at least one set of a base part and vertical wall parts which, together, delimit a mould cavity having a volume with a depth which is greater than or equal to one centimeter, said pump means being designed to supply said mould cavity with an amount of water which substantially corresponds to said volume of said mould cavity from said water reservoir at a start of a freezing cycle, release means being provided for releasing a frozen ice cube from said mould cavity after said freezing time. The apparatus comprises a thermoelectric element and an ice cube tray which is connected thereto in a thermally conductive manner. The apparatus is provided with its own internal water reservoir which, at the start of a production cycle, can be filled once with a desired amount of water. From the reservoir, the water can be metered to a mould cavity of an ice cube tray with the aid of water-metering means, for example a pressure pump. The mould cavity is at least one centimeter deep and consequently is suitable for the production of ice cubes with a thickness of greater than one centimeter. Control means with a timer unit then ensure that the thermoelectric element is supplied with current for a defined, set freezing time, in such a manner that heat is extracted from the ice cube tray. On the other side of the thermoelectric element, this heat is released again to the environment. After the freezing time has elapsed, release means which release the ice cube from the tray come into operation. The ice cube is collected and removed by removal means which are arranged beneath or next to the tray. The apparatus may comprise its own battery power supply or may be equipped with a plug for connection to an electricity grid. Consequently, the invention provides an ice cube apparatus which operates completely independently. The apparatus simply has to be switched on after the water reservoir has been filled with a defined amount of water. The amount of water can be adapted to the desired number of ice cubes. Then, the apparatus will produce a plurality of ice cubes in succession, in a continuous process, which are collected and removed via the removal means. The apparatus is structurally simple, inexpensive to produce and hygienic to use. The various components interact virtually without any noise and make it possible to construct an apparatus of very small dimensions, for example with a housing which holds the various components and measures 15xc3x9715xc3x9725 cm. Consequently, the apparatus is eminently suitable for use at home and in hotel rooms and the like. The use of mechanical components, such as controllable valves, is limited, which increases the reliability of the apparatus and means that maintenance is limited to a minimum. Surprisingly it has been found that the time which is required to produce a series of ice cubes of standard size, for example approximately 8 cm3, using the apparatus according to the invention is less than 10 minutes, and in particular only a few minutes.
Preferred embodiments of the invention are defined in the subclaims.